Electricity

Question 1

What is the mains voltage in the uk?

Answer 1

230 V

Question 2

Direct current…

Answer 2

-Charge only moves in one direction
-the size of P.D and current stay the same
-Cells and batteries supply D.C
-Electronic devices use D.C
-D.C cannot be transferred efficiently over large distances

Question 3

Alternating Current…

Answer 3

-Movement of charge changes direction
-the size of P.D and the current constantly changes magnitude!
-A.C generated by power stations. Used in lights and heating

Question 4

What does d.c stand for?

Answer 4

Direct current

Question 5

What does a.c stand for?

Answer 5

Alternating current

Question 6

What is the frequency of the mains supply?

Answer 6

50!!

Question 7

What is the colour of the
Earth wire?
Live wire?
Neutral wire?

Answer 7

Green
Brown
Blue

Question 8

Name all the components of a plug.

Answer 8

Earth wire, live wire, neutral wire, cable grip and Fuse

Question 9

What is the fuses job?

Answer 9

If too large a current flows the wire becomes hot and breaks the circuit
-This prevents appliances from overheating if too high a current flows

Question 10

How do you choose the right fuse?

Answer 10

Step 1: find the power rating of the supply e.g 1400 watts
Step 2: calculate the current by dividing 1400 watts by 230 volts(uk mains) =6
Step 3:select appropriate fuse so 10 A

Question 11

Why is earth wire important?

Answer 11

Prevents electrocution